New Rotor Magnet, Now Cant Idle..

Did you check the stator to rotor clearance? Not sure if a 750 is too similar to my TR6C, but when I swapped out my rotor the new one was a little wider than original and I had to omit the spacer behind it so it wouldn't touch the rotor cover. Maybe check that. Aside from that I can't think of anything related that would cause it not to idle. Sorry not much help.........

points ignitions are not a real voltage sensitive ignition, why don't you put a volt meter on it and see what voltage you are getting at idle, do you have a battery or not?

Yea The new rotor seemed tight, I could get around the stator with a .006 feeler gage, but anything much thicker was binding. So I threw back on my old rotor and I am still having the same issues. I am running batteryless with a Sparx reg/rec/cap combo. I had it running really well with this combo before, so i dont know why after swapping the old one back on , its still not idling. I would test the voltage but it wont idle at all, the engine will run if i keep the throttle on, but not idle. So I am thinking it could be the carbs? I took apart the carbs and all i could notice was that one of the float bowls was a bit low. I am going to check the needles and jets when i get back there.

The strange thing is that even when i was adjusting the mixture screw it was not affecting how it was running before it dies out... I also put two brand new plugs in just in case..

Running out of ideas here.

on Amals, if you are not getting any effect out of the mixture screw, then the pilot jet is plugged, to clear it, you need to remove the adjuster screw and put a pilot cleaning tool or a piece of guitar string/ piano wire in there all the way to the other side of the carb and un-plug the pilot jet. when it's clear you should be able to fill the bowl with gas by pushing down on the tickler and then take a can of carb cleaner with a tube on it, put it all the way in and when you shoot it in the gas will shoot out of the tickler button. that will tell you the jet is clear going down to the bowl.